Monthly Archives: January 2010

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“Taking Flight” is a temporary art exhibition in our butterfly center, displaying the artwork of 6th – 12th grade students from three of the seven YES Prep Public School campuses. Inspired by science, or simply a love of nature, they are all wonderful depictions of different butterflies and insects – and a beautiful illustration of the intersection of science and art.

Today we highlight the work of Alyssa Valdez. She gave us a little insight into her work and the carnivorous caterpillar in the q&a below.

The Predator
Alyssa Valdez, 11th gradeArtist Statement: “The carnivorous caterpillar caught my eye because it’s unusual and something you don’t see every day. This painting portrays two perspectives on the carnivorous caterpillar. The first is a close-up of a carnivorous caterpillar as he is preparing to eat his prey. The second is of his attack on a fruit fly.”

1. What was your inspiration for creating this piece? Why did you choose to portray carnivorous caterpillars?

My goal was to portray an insect that was both disgusting and unusual…the problem was I didn’t know what I was going to choose. One day my boyfriend brought up carnivorous caterpillars in a conversation, and I knew I wanted to portray [them]. It was something out of the ordinary. Plus, these caterpillars are so small, but their name makes them sound so scary and intimidating.

2. The subject is a little gruesome – but you rendered it with very cheerful colors. Why?

I wanted to zoom in on the detailed profile of the insect, as if someone was taking notes and sketching to capture the caterpillar in action. I was also experimenting with colors with this piece. I wanted to exaggerate the action, and I wanted it to be eye catching. I had the idea, “what if something so gruesome could look so beautiful?” I hope it makes people stop and take a second look.

3. What role should art play in science?

I think the goal of art in science is to make observations and capture aesthetics. I find chicken scratch short notes and rough sketching to be artistic, so it only seems appropriate to mesh the two together.

4. Do you think you’ll use scientific concepts for your art in the future?

Gruesome is my best friend. In science there are many things that people might find morbid or gruesome, but I find fascinating. For example, I have recently learned about and become interested in forensic sciences and how insects have been used to help solve murder crimes and mysteries. The world isn’t always pretty rainbows and cute kittens. I like to magnify the things people don’t always see, even some of the things that could make people’s stomachs turn.

Don’t miss Alyssa’s “The Predator” – or any of the other beautiful works of art now on display in “Taking Flight,” on the lower level of the Cockrell Butterfly Center. The exhibition will be available through March 31.

Our Guest blogger today is Dr. Todd Disotell, a professor of anthropology and a molecular primatologist at New York University’s Center for the Study of Human Origins. He will be speaking at HMNS on Feb. 9 at 6:30 p.m. about new molecular analytical techniques and how mapping whole genome sequences has affected what we know about the past. In his blog below, Dr. Disotell debates a recently proposed theory that humans are more closely related to orangutans than chimpanzees – a theory he disagrees with.

This past summer upon the publication of a paper by a colleague, I found myself at the intersection of a 25 year old hypothesis, the latest research in genomics and bioinformatics, and popular culture. Jeffrey Schwartz of the University of Pittsburgh and his coauthor, John Grehan of the Buffalo Museum of Science published an updated version of their hypothesis that orangutans are more closely related to humans than are chimpanzees in the Journal of Biogeography. This intrigued me because in my final year of graduate school, my advisors and I published one of the earliest papers utilizing DNA sequence data supporting the growing consensus that chimpanzees were our closest relative, followed by gorillas, and much more distantly orangutans.

Perhaps due to my working in New York City, a producer from the Daily Show with Jon Stewart called me at my office and wanted to know if I was willing to be interviewed about Schwartz’s hypothesis. As a fan I readily agreed and correspondent John Oliver was dispatched to my laboratory to interview me. During the course of the interview in which I stated that the hypothesis flew in the face of all known genetic evidence, I opined that I would at least get to write a counter paper and perhaps a counter-counter paper if Schwartz responded. That got me thinking about newly available genomic data that was now available in various databases which had not been fully analyzed.

I then downloaded the complete genome alignments that included human, chimpanzee, gorilla, orangutan, macaque, marmoset, lemur, and galago. After writing a series of Python scripts (an open source computer programming language) to parse and reformat the masses of sequence data, I chose the first 1 million bases of each chromosome for which all of the above species were represented. I then used well characterized statistical and analytical techniques to infer the evolutionary history of each DNA region. Not surprising to me, the analysis of each region convincingly rejects the hypothesis that orangutans are more closely related to humans than are chimpanzees. Furthermore, when these 30 million DNA bases are used to estimate the time of divergence between humans, chimpanzees, and orangutans using molecular clock techniques, the orangutan appears to have diverged at over twice the age chimpanzees have from humans.

These results are not at all surprising to the absolute majority of paleoanthropologists and evolutionary primatologists. However, it is still worthwhile to occasionally revisit theories and hypotheses that we now take for granted when new data are generated and new analytical techniques are developed. In this genomic age, as the genomes of more and more species and even individuals within species are being sequenced, a whole new class and scale of analyses can be carried out from the keyboard.

Early next month, a large rodent will emerge and look at the ground. If he sees his shadow, he scurries back into his winter den, and it is said that winter will continue for six more weeks. If there is no shadow, he stays out, and an early spring is in the offing. But, how does the groundhog’s shadow let us know how long the winter will be?

Understanding this forecast begins with knowing the cycle of the seasons. The Earth orbits the sun with its axis tilted by about 23.5 degrees. On about June 21 each year, the North Pole is tilted as much as possible towards the sun and the sun takes its highest path across our sky. This is the summer solstice for us and the winter solstice for the Southern Hemisphere. Six months later, the South Pole is tilted as much as possible towards the sun and the sun takes its lowest path across our sky. Dec. 21 is our winter solstice and the summer solstice below the equator. Halfway between these dates, on about March 20 and September 22, the sun is overhead at the equator and both poles are on the day-night terminator. As everyone then has the same amount of daylight and nighttime, these dates are the equinoxes. We can think of the solstices and equinoxes as ‘quarter days.’

We have come to define our seasons as beginning at the solstices and equinoxes. Northern European pagans, however, paid equal if not more attention to dates about halfway between the solstices and equinoxes, called the ‘cross-quarter days.’ For them, seasons began at the cross-quarter days, while the solstices and equinoxes were the midpoints of the seasons. A while ago,I blogged about the cross-quarter day between the fall equinox and the winter solstice, Samhain, and explained how its traditions influenced our Halloween celebrations. Now, as January ends and February begins, we are approaching the halfway point between the winter solstice and the spring equinox–another cross-quarter day.

For the Celts, this was Imbolc (pronounced as if there were no ‘b’), sacred to Brigid, goddess of fine craftsmanship, healing, poetry and generally anything involving the higher faculties of mankind, as the Celts understood them. Among the traditions associated with Imbolc was the belief that Brigid’s snake would emerge from its winter resting place and test the weather. Germans used a hedgehog to forecast the weather. If the animal in question scurried back into its burrow, it was a sign that much more winter was ahead.

In the time before the Celts encountered the solar calendar established by Julius Caesar, the actual date of Imbolc varied from year to year. With the adoption of the Romans’ calendar, Imbolc came to be observed on Feb. 1 (just as observations of Samhain moved to Nov. 1 and the eve of that day). The actual midpoint between the winter solstice and the vernal equinox is Feb. 3.

Feb. 2 is Candlemas Day, the 40th day of Christmas (with Christmas as day 1). Christians observe this as the presentation of the baby Jesus at the temple. As has often occurred when Christian observances nearly coincide with pagan ones, folklore from one became attached to the other. Thus, as northern Europeans began to migrate to America, they had a weather forecast descended from Imbolc associated with Feb. 2. Upon arriving here, they replaced the hedgehog (not native to America) with a uniquely American animal, the groundhog.

Let’s look more closely at the rules for the Groundhog Day forecast. If we don’t want the groundhog to see his shadow on Feb. 2, then we must not want sunshine that day. Good weather (bright and sunny) is a bad omen, while bad weather is a good omen. This page quotes some sayings from Europe and America which make this explicit. To appreciate this apparent reverse psychology, let’s consider another day on which bad weather is welcome: Christmas.

Think back to early last month, when Houston experienced a snowfall on Dec. 4 (it had never snowed that early in the winter here in Houston). Think back even further to our Christmas Eve snowfall in 2004 (our first white Christmas ever). Such unusual weather (for us) reminded many of favorite holiday songs such as ‘Let it Snow’ or ‘White Christmas.’ “Now this feels like Christmas,” many told themselves. Now recall the bitter cold a few weeks ago this January. Did anyone break into song? Was anyone saying, “At least this feels more like January?” Why the double standard? Why is the type of weather we welcome at Christmas just bad weather when it happens in January?

It seems that people who made their living off the land and thus depended on regular seasonal changes constantly looked for reassurance that the natural cycles were functioning properly. A winter that was truly wintry was therefore a good omen. If winter happened when it should, then perhaps spring, summer, and the harvest would occur in their proper times, and everything was in balance. If winter were warm and sunny, however, then something was wrong. If winter was not happening in its season, then other seasons might also fail to appear. In particular, people feared that failing to have a true winter at the proper time would require ‘remedial’ winter during springtime.

In time, the winter solstice and the cross-quarter day, Imbolc (later Christmas and Candlemas Day) came to stand in for the whole winter. Thus, wintry weather on Christmas and on Feb. 2 is a good omen, while bright, sunny weather on these days is a bad omen. And so, the sight of his shadow frightens the groundhog back into his burrow.

The winter of 2009-2010 has been more severe than usual, not just in Houston but across much of the Northern Hemisphere. Thus, many can sympathize with those who are looking for any possible sign of spring. As it turns out, there is a sign of approaching spring that becomes noticeable as February begins–the greater height of the sun.

Ever since the winter solstice, we have seen the sun take a slightly higher path across our skies each day. However, the difference in height is difficult to notice until February. This is because the height of the sun during the year varies like a sine wave. There is little variation near the maximum and minimum; most of the change occurs midway between these points. During February, March and April, the sun’s higher path is more apparent than in January. All shadows, including those of groundhogs, get noticeably shorter each week. If you can’t measure shadows during the day, try observing the same change in the position of sunset. From the same vantage point, notice where the sun sets once each week during February, March and April. You’ll notice a distinct shift towards the north (towards the right as you face sunset in the west) with each observation. Since this happens every year as winter turns to spring, you now have reliable assurance that spring is on the way. No need to be afraid of shadows.

There are so many different kinds of crystals all around us, but just what are they anyway?

Put simply, a crystal is a grouping of molecules or atoms that is organized in a specific way. Every crystal has a unique shape and properties that make it recognizable. In today’s experiment, we will be working with sugar crystals which are oblong and slanted on the ends.

There are a couple of things going on that contribute to the growth of sugar crystals in this experiment. First, you will be creating a supersaturated solution by heating a saturated sugar solution and allowing it to cool.

Supersaturated solutions are solutions that are so full (of sugar in this case), that they are unstable. The solution you will create will contain more sugar (the solute) than it can hold in a liquid form. Therefore, the sugar must come out of solution – forming what is called a precipitate (also known as yummy rock candy). The second mechanism that helps to form the sugar crystals is evaporation. Slowly, the water evaporates from your solution. As this happens the solution becomes even more saturated with sugar and the sugar will continue to come out of the solution and form sugar crystals.

What you are left with is a delicious science treat! Make sure to only eat a little at a time and keep the rest sealed in a baggie. Also, don’t forget to brush your teeth; it is pure sugar after all! Have fun in your kitchen lab and don’t forget to be safe! Always include an adult when trying new experiments.

What to do:
1. Dump one cup of sugar and ½ cup of water into your saucepan. Don’t stir it!
2. Find your adult and have them help you put it onto the stove over medium-high heat. Wait for the mixture to come to a boil and let it boil for one minute without stirring. If you want colored rock candy, you may add some food coloring while it boils.
3. Instruct your handy adult to pour this mixture into the two canning jars.
4. Find a place on your counter that you can let the two jars sit undisturbed for two weeks.
5. Observe them once a day. Slowly, crystals begin to form. When you see a crust form on top of the jars, use a spoon to carefully break the crust so the water can continue to evaporate. Don’t do anything else to your jars other than this!
6. When you feel like you have enough crystals of the right size, have an adult help you remove them from the jar using a dull table knife.
7. Eat and enjoy! Don’t forget to brush your teeth, it is sugar after all!